The invention relates to security laminates for use as a security feature on or in documents.
Documents of value such as passports, identification cards, entry passes, ownership certificates, financial instruments, and the like, are often assigned to a particular person by personalization data. Personalization data, often present as printed images, can include photographs, signatures, fingerprints, personal alphanumeric information, and barcodes, and allows human or electronic verification that the person presenting the document for inspection is the person to whom the document is assigned. There is widespread concern that forgery techniques can be used to alter the personalization data on such a document, thus allowing non-authorized people to pass the inspection step and use the document in a fraudulent manner.
A number of security features have been developed to authenticate the document of value, thus preventing forgers from producing a document, which resembles the authentic document during casual observation, but lacks the overt or covert security features known to be present in the authentic document. Overt security features include holograms and other diffractive optically variable images, embossed images, and color-shifting films, while covert security features include images only visible under certain conditions such as inspection under light of a certain wavelength, polarized light, or retroreflected light. Even more sophisticated systems require specialized electronic equipment to inspect the document and verify its authenticity. Often, these security features are directed at verifying the authenticity of the parent document, but convey little information regarding the authenticity of the personalization data. Further features that convey information about, or prevent, tampering with the personalization data are needed.
Of particular interest today is the ability to be able to determine that a forgery has been attempted without the need to resort to a special tool. There is a strong desire to be able to determine such tamper attempts using normal lighting conditions such as diffuse incandescent or fluorescent light sources.
Commonly, the personalization data on documents of value is protected by encapsulation of the printed images between laminated layers, one or more layers of such laminates often being designed to show visible evidence of tampering. Production of a document which protects the personalization data by encapsulation requires hardware which can perform the combined functions of printing and heat laminating, often including the associated functions of roll feeding and die cutting. While such hardware is available, it can be rather complex and expensive, often beyond the reach of smaller issuing authorities.
Of additional concern is that typically the laminate and the data being protected by the laminate are resident in two discrete and separate layers and it is a commonly attempted practice to carefully separate the two layers and alter the data without inflicting any visible damage to the security document. There would be great utility and value in a technology which enabled simple, fast and inexpensive production of personalized documents of value having durability and tamper resistance.